Double diaphragm pump



FIG. 1 is a front elevational view of a double diaphragm pump showing my new design;

FIG. 2 is a right side elevational view thereof, the side opposite being substantially a mirror image;

FIG. 3 is a rear elevational view thereof; and,

FIG. 4 is a top plan view thereof. 

The ornamental design for a double diaphragm pump, substantially as shown and described. 